Official Luthiers Forum!

Are there any tricks to apply a little glue as needed to the edge of a spruce top that I will be joining ? Last time the excess glue left some little spots.

The way I read this, the implication is that your excess glue left spots on the wood last time you joined a top. I think the solution is to join your plates before you reduce the thickness to final dimensions.

Whether you remove excess glue immediately or after it sets up a bit is not critical, if, after you have joined the plates, then you finish plane or sand to final thickness. The act of finish thicknessing by sanding and/or planing will remove any excess glue.

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